Callisto (Sol V-iv)
Callisto is a large, icy, dark-coloured, low-density outer moon of Jupiter (Sol V) that is scarred with impact craters and ejecta. Although much of this has been built over, mined, developed and in other ways transformed over the last few millennia a return to a more natural state has been cultivated. It has a diameter of about 4800 km. It has a rich and vibrant history; for the past three thousand years it has been almost entirely populated by virtual entities within environments designed by the ruling S2: the Game Master.
Orbital Space: Callisto is encircled by a single sparse orbital band. The band is made up of several dozen spherical habitats, each some ten kilometers across. These house the tourist/participants of the Game Master's scenarios, as well as limited facilities for non-participant tourists or other visitors. In addition, the moon is orbited by a number of relay satellites used to transmit the Game Master's scenarios to the Solsys localnet and the Known Net beyond.
Orbital Population: 22 million sophonts (a broad mix of races and clades, mostly various near-baselines and Superiors, with some others - the population is all transient, staying for periods ranging from several days to several months, depending on their ability to persist in the local virtual environment.)
Surface Population: 1 sophont - the S2 transapient known as The Game Master.
Virtual Population: Hundreds of millions to many billions of visitors.
Government: The Game Master is the undisputed ruler of Callisto and its immediate orbital environs. While e theoretically defers to the Solar Organization, in matters on, within, or immediately around Callisto, eir authority is functionally absolute.
Planetary Surface: In many ways, Callisto's surface is very similar to that of Europa. Other than communication and anti-impact systems, the surface is largely barren and undeveloped. The most obvious difference between the surfaces of the two moons is that there are no sophonts living on the surface of Callisto, that the various installations deployed across the surface are built using Second Singularity technology and are therefore largely incomprehensible to modosophont intelligence, and that the communications systems are much more extensive.
Beneath the icy crust of Callisto lies a buried ocean, even deeper than that of Europa. Like the ocean of Europa, the ocean of Callisto has been modified to support an extensive ecosystem. Unlike Europa, the purpose of this ecosystem is not to provide a home for sophont inhabitants, but to operate as a biological computing substrate running the virtual reality scenarios of the Game Master. According to the accounts of the few transapient visitors who have been allowed to observe them, the artificial lifeforms of the ocean are simple and have no more variation or diversity than is necessary to create a stable ecology focused on maintaining large reef like structures of biocomputing substrate. Most of the organisms in the ocean, and the substrate itself, share and transmit data via modulated light flashes, filling the darkness of the abyssal sea with a continuous storm of multi-colored light. Periodic recordings of the Callisto virtualities are uploaded into the Known Net using the surface transmitters, making the scenarios available to most of Terragen civilization.
The Game Master's scenarios, colloquially referred to as the Diamond's Arm, depict an alternative history in which the ahumans won the early battles between the ahuman and hu-friendly AIs and went on to exterminate or enslave all biont and hu-friendly life in the Terragen Bubble. While widely and generally dismissed as historically inaccurate and sensationalist apocalyptic nonsense by serious historians across the Civilized Galaxy and most of what is considered 'polite society' in SolSys the "Diamond's Arm" virtualities have becomes a major tourist attraction within some segments of Terragen civilization. Tourists come from across the Terragen Sphere to take part in the various scenarios directly, living in the habs of Callisto's single orbital band and using high grade virtuality systems to suppress their memories of their lives in the real world, making their life as a desperate refugee or hider or slave in the Diamond Arm seem as if it is their only existence. For reasons known only to itself, the longest amount of time that the Game Master allows any participant to directly experience a scenario is three Old Earth months. However, the rate of attrition within the different virtualities is generally quite high and many visitors last no more than a few days, or even hours, before experiencing virtual death and being ejected back into the ril. The Game Master does not allow any single participant to experience the Diamond Arms directly more than once, and so once ejected they have little choice but to leave Callisto once again, while someone else takes their place.
History and Comments: A major trade, communications and industrial hub during both the interplanetary and federation era. Few of these settlements survived the Technocalypse. The First Federation era saw a new wave of settlers, and Callisto joined Vesta as among the main power centres of the Sol System. At its peak during the late Federation period the population - on and beneath the surface and in the orbitals - numbered some 12 billion. The expansion age, wormholes, cheap amat ships and fast and comfortable reactionless drive ships and the opening of the frontier led to a slow exodus over several centuries, as waves of emigrants sought a better life in the wide-open frontiers.
The Version War era saw a brief repopulation by refugees, although this never reached late Federation levels. The huge crowds and crush of populace are now long gone, and the major arcologies and habitats on and beneath the surface now are given to a flourishing tourist trade, entertainment, the arts, virchistorical tours and totalrecalls, a Genetekker revivalist colony and, in some areas, a rather flourishing red light industry.
Towards the end of the Post-Comp era the population had dwindled to just 4 billion sophonts on the surface and in orbit, unified as the Tribal Mind Republic of Callisto. The population was diverse 70% (and growing) of the population being virtual. Fluid lifestyles between the virch and Ril were common and models showed the rather staid culture of the TMRC would likely settle into a solipsist virtual group mind within a few centuries. In 7221a.t. the accuracy of these forecasts was disrupted as an ascension event, the first in millenia for the moon, occured within the Tribe Mind. Nearly a third of the population merged into an S1 entity known as the Castilian. The Republic remained with de facto power residing in the hands of the new hyperturing. Castilian fostered good relations with the Arcturus institute of alternate history and sparked a minor renaissance in the study of sociology and history on the moon. The academic work performed there was of good quality though had no significant impact on the field. The next major upheaval occured two centuries later when the majority of the remaining tribe mind, already comprehensively linked to Castilian, merged with em in another ascension event that would give rise to the S2 games master. The few million remaining modosophonts abandoned the Republic amicably, leaving the moon over the next few decades for orbit or further destinations, as the Diamond arm project began in earnest.
For details about Callisto in the Current Era, see here.